Find the arithmetic mean of 123456, you need to divide the sum of the digits by the number of digits.Sum of digits: 1 + 2 + 3 + 4 + 5 + 6 = 21Number of digits: 6Arithmetic mean: 21 / 6 = 3.5The arithmetic mean of 123456 is 3.5.Alternatively, you can also calculate the mean using the formula:Mean = (Sum of all values) / (Number of values)[tex].[/tex]